- (void)viewDidLoad { [super viewDidLoad]; //增加監聽，當鍵盤出現或改變時收出消息 

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(keyboardDidShow:)

                                                 name:UIKeyboardWillShowNotification

                                               object:nil];

//增加監聽，當鍵退出時收出消息

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(keyboardDidHide:)

                                                 name:UIKeyboardWillHideNotification

                                               object:nil];

}

//當鍵盤出現或改變時調用

- (void)keyboardDidShow:(NSNotification *)notification{

    NSDictionary *userInfo = [notification userInfo];

    CGSize keyboardSize = [[userInfo objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    _keyBoardHeight = keyboardSize.height;

    [self changeViewYByShow];

}

 

//當鍵盤隱藏時調用

- (void)keyboardDidHide:(NSNotification *)notification{

    _keyBoardHeight = 0;

    [self changeViewYByHide];

}

#pragma mark - private methods

- (void)changeViewYByShow{

    [UIView animateWithDuration:0.2 animations:^{

        CGRect rect = self.view.frame;

        rect.origin.y -= self.keyBoardHeight;

        self.view.frame = rect;

    }];

}

- (void)changeViewYByHide{

    CGRect rect = self.view.frame;

    rect.origin.y = 64;

    self.view.frame = rect;

}